1. Field of the Invention
The present invention relates to a connector housing having a shape to prevent short shot of resin material to partitions and sidewall portions of a terminal accommodating chamber and also to a manufacturing method of the connector housing.
2. Description of the Related Art
FIG. 8 shows an example of a prior art connector housing.
A connector housing 31 is formed of synthetic resin has a plurality of terminal accommodating chambers 32 arranged in two steps. The terminal accommodating chambers 32 are sectioned with vertical partitions 33, horizontal partitions 34, upper and lower wall portions 35,36, and right and left wall portions 37,38.
A terminal 39 is inserted into each of the terminal accommodating chambers 32 through respective rear openings and is primarily engaged by means of a resilient engaging lance (not shown) arranged inside the terminal accommodating chamber 32. The terminal 39 has, in the front half, a boxlike electrically contacting portion 41 having inside a spring portion 40 for contact and a wire pressure-welding portion 42 in the rear half. The terminal 39 of this example is a female type, and a male type terminal (not shown) is accommodated in a connector housing 31.
The connector housing 31 is integrally provided, through long hinges 44, with top and bottom pair of rear holders 43 for secondary engaging the terminal 39. Each of the rear holders 43 has an engaging projection 45 for engaging the terminal. And, the rear holders 43 are inserted into the connector housing 31 through respective rear openings 46. The engaging projection 45 enters inside terminal accommodating chamber 32 so as to engage a rear end 41a of the electrically contacting portion 41 of the terminal 39. As described above, the terminal 39 is double locked by means of the engaging lance and the engaging projection 45. The hinges 44 are accommodated inside the openings 46.
The connector housing 31 is formed by injecting a melted resin material into an unshown metal mold and cooling down the resin material. At the same time, the rear holders 43 and the hinges 44 are integrally formed therewith.
With respect to the above connector housing 31 and the manufacturing method thereof, however, especially in case the pitch between the terminals 39 has to be small, thickness of the partitions 33,34 is partially likely to become less than a defined one because of a short shot in the injection molding, because the vertical partitions 33 and the horizontal partitions 34 have to be thin, thereby causing the rare-short due to poor insulation between the terminals.
And, there could be a case of thinly making the sidewalls 37,38 for downsizing the connector housing 31, and also thickness of the sidewalls 37,38 is likely to become less than a determined one, also thereby causing the rare-short due to poor insulation between the terminals and the outside of the housing 31.
Besides, the rear half portions of the sidewalls 37,38 have to be thinly made because a space for accommodating the hinges 44 have to be arranged, which also brings about the short shot in the injection molding of the sidewalls 37,38.
In view of the foregoing, an object of the present invention is to provide a connector housing and a manufacturing method thereof, wherein a short shot on partitions and sidewall portions of a connector housing in the resin-molding can be securely prevented so as to secure a defined thickness of the partitions and the sidewall portions.
In order to achieve the above-described object, as a first aspect of the present invention, a connector housing comprises: an outside wall having an upper and lower walls and sidewalls; horizontal partition and vertical partition which form terminal accommodating chambers inside the outside wall; and a thin sidewall portion formed on each of the sidewalls and being thinner than a remaining portion of the corresponding sidewall, wherein a short shot preventing rib is longitudinally formed on the thin sidewall portion integrally therewith in a generally vertical center thereof.
As a second aspect of the present invention, in the structure with the above first aspect, the short shot preventing rib projects outside over the remaining portion continuing from the thin sidewall portion.
As a third aspect of the present invention, in the structure with the above first or second aspect, the short shot preventing rib is arranged in a line with the horizontal partition.
As a fourth aspect of the present invention, in the structure with the above third aspect, the short shot preventing rib is formed thicker than the horizontal partition.
As a fifth aspect of the present invention, a manufacturing method of connector housing comprises the steps of: setting a mold for molding a connector housing which has a short shot preventing rib on each of thin sidewall portions formed on both side walls; arranging a gate of a runner at a position corresponding to an outside wall of the connector housing; and injecting a melted resin material into the mold through the gate for forming the connector housing, wherein the short shot preventing rib is formed on each of the thin sidewall portions integrally therewith.
According to the above-described structure of the present invention, the following advantages are provided.
(1) In the injection molding, because the melted resin material flows from the thick sidewall portion side to the rib side, the thin sidewall portion is securely filled up with the resin material. Therefore, the short shot on the thin sidewall portions can be prevented and the insulation between the terminals in the terminal accommodating chambers and the outside can be secured, thereby preventing the rare-short. And, because the melted resin material is introduced from the rib side toward the horizontal partitions and further is introduced from the horizontal partitions to the vertical partitions, the short shot on the portions and on the partitions can be prevented. Therefore, the insulation among the terminals in the accommodating chambers can be secured, thereby preventing the rare-short.
(2) After the melted resin material has flown into the thick sidewall portion, a flow of the resin material to the rib side increases, thereby improving the above effect.
(3) Because the resin material smoothly flows into the horizontal partition from the rib side, the horizontal partition and the vertical partition can be securely filled up with the resin material.
(4) Because a cross section of the rib is large, quantity and velocity of the resin material flown into the rib increase, thereby further improving the above effects.